Comment 1 for bug 1477534

http://logstash.openstack.org/#dashboard/file/logstash.json?query=message:%5C%22neutron.agent.linux.utils%5C%22%20AND%20message:%5C%22Stderr:%20RTNETLINK%20answers:%20File%20exists%5C%22%20AND%20tags:%5C%22console%5C%22

7 hits in 7 days, check and gate, all failures. Saw it here also:

http://logs.openstack.org/90/245990/1/check/gate-tempest-dsvm-neutron-large-ops/cb9d987/logs/devstacklog.txt.gz#_2015-11-17_03_25_52_496

2015-11-17 03:25:51.480 | Option "verbose" from group "DEFAULT" is deprecated for removal. Its value may be silently ignored in the future.
2015-11-17 03:25:52.496 | 2015-11-17 03:25:52.496 27841 ERROR neutron.agent.linux.utils [-] Command: ['ip', 'netns', 'exec', u'qprobe-bf99c3e1-e331-46af-b67c-e10e471ea2a0', 'ip', '-6', 'addr', 'add', 'fdb2:ed41:114c:0:f816:3eff:feeb:d62c/64', 'scope', 'global', 'dev', u'tapbf99c3e1-e3']; Exit code: 2; Stdin: ; Stdout: ; Stderr: RTNETLINK answers: File exists
2015-11-17 03:25:52.497 | 2015-11-17 03:25:52.497 27841 ERROR neutronclient.shell [-]
2015-11-17 03:25:52.497 | Command: ['ip', 'netns', 'exec', u'qprobe-bf99c3e1-e331-46af-b67c-e10e471ea2a0', 'ip', '-6', 'addr', 'add', 'fdb2:ed41:114c:0:f816:3eff:feeb:d62c/64', 'scope', 'global', 'dev', u'tapbf99c3e1-e3']
2015-11-17 03:25:52.497 | Exit code: 2
2015-11-17 03:25:52.497 | Stdin:
2015-11-17 03:25:52.497 | Stdout:
2015-11-17 03:25:52.497 | Stderr: RTNETLINK answers: File exists